es6.weak-map.js 1.8 KB

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  1. 'use strict';
  2. var each = require('./_array-methods')(0)
  3. , redefine = require('./_redefine')
  4. , meta = require('./_meta')
  5. , assign = require('./_object-assign')
  6. , weak = require('./_collection-weak')
  7. , isObject = require('./_is-object')
  8. , getWeak = meta.getWeak
  9. , isExtensible = Object.isExtensible
  10. , uncaughtFrozenStore = weak.ufstore
  11. , tmp = {}
  12. , InternalMap;
  13. var wrapper = function(get){
  14. return function WeakMap(){
  15. return get(this, arguments.length > 0 ? arguments[0] : undefined);
  16. };
  17. };
  18. var methods = {
  19. // 23.3.3.3 WeakMap.prototype.get(key)
  20. get: function get(key){
  21. if(isObject(key)){
  22. var data = getWeak(key);
  23. if(data === true)return uncaughtFrozenStore(this).get(key);
  24. return data ? data[this._i] : undefined;
  25. }
  26. },
  27. // 23.3.3.5 WeakMap.prototype.set(key, value)
  28. set: function set(key, value){
  29. return weak.def(this, key, value);
  30. }
  31. };
  32. // 23.3 WeakMap Objects
  33. var $WeakMap = module.exports = require('./_collection')('WeakMap', wrapper, methods, weak, true, true);
  34. // IE11 WeakMap frozen keys fix
  35. if(new $WeakMap().set((Object.freeze || Object)(tmp), 7).get(tmp) != 7){
  36. InternalMap = weak.getConstructor(wrapper);
  37. assign(InternalMap.prototype, methods);
  38. meta.NEED = true;
  39. each(['delete', 'has', 'get', 'set'], function(key){
  40. var proto = $WeakMap.prototype
  41. , method = proto[key];
  42. redefine(proto, key, function(a, b){
  43. // store frozen objects on internal weakmap shim
  44. if(isObject(a) && !isExtensible(a)){
  45. if(!this._f)this._f = new InternalMap;
  46. var result = this._f[key](a, b);
  47. return key == 'set' ? this : result;
  48. // store all the rest on native weakmap
  49. } return method.call(this, a, b);
  50. });
  51. });
  52. }